Contact voltage and magnetic fields as possible factors in leukemia--pilot study. (Update).A recent Electric Power Research Institute (EPRI EPRI Electric Power Research Institute EPRI European Parliaments Research Initiatives ) study investigated the correlation between magnetic fields magnetic fields, n.pl the spaces in which magnetic forces are detectable; created by magnetostrictive ultrasonic scalers to cause the tips of instruments such as ultrasonic scalers to vibrate. and contact voltages measured in a pilot sample of residences. Results of the study appeared in Volume 23 of Bioelectromagnetics (2002) under the title "Contact Voltage Measured in Residences: Implications to the Association Between Magnetic Fields and Childhood Cancer." Researchers Rob Kavet and Lou Zaffanella also considered the extent to which physical contact with voltage sources A voltage source is any device or system that produces an electromotive force between its terminals OR derives a secondary voltage from a primary source of the electromotive force. could lead to measurable amounts of contact current. The authors concentrated on two possible sources of contact current exposure: 1) the voltage between water fixtures such as faucets and the metallic frames of appliances, and 2) the voltage between water fixtures and the earth. The second kind of voltage, which from a health perspective appears to be the more significant one, could include a voltage between water lines and metallic drainpipes. A bathing child playing with a faucet or spout with a wet hand could complete a circuit driven by this voltage, which may vary from several millivolts to over a volt volt [for Alessandro Volta], abbr. V, unit of electric potential and electromotive force. It is defined as the difference of electric potential existing across the ends of a conductor carrying a constant current of 1 ampere when the power dissipated is 1 watt. . Contact with the drain occurs via bath water, which is conductive conductive having the quality of readily conducting electric current. conductive flooring flooring or floor covering made specially conductive to electrical current, usually by the inclusion of copper wiring that is earthed . (In many homes with new construction, plastic pipes or nonconductive drains eliminate this exposure.) Dosimetric modeling suggests that upon contact, a current of up to tens of microamperes could flow into the hand, producing a dose within the bone marrow of the arm that far exceeds the dose resulting from exposure to ambient Surrounding. For example, ambient temperature and humidity are atmospheric conditions that exist at the moment. See ambient lighting. levels of magnetic fields. In the pilot study of 36 residences with conductive plumbing, the voltage between water pipes and the earth was statistically significantly correlated with measured residential magnetic fields. Given this correlation, the magnitude of the dose to relevant tissue, and the possibility of exposure while bathing, the authors believe this exposure deserves further research attention as a factor that may help explain reported associations between magnetic fields and childhood leukemia leukemia (l  kē`mēə), cancerous disorder of the blood-forming tissues (bone marrow, lymphatics, liver, spleen) characterized by excessive production of immature or mature .
(Adapted with permission from EPRI Journal[R] Online, a publication of EPRI.) |
|
||||||||||||||||
Printer friendly
Cite/link
Email
Feedback
Reader Opinion